Covers which are applied to cylinders of rotary printing machines are preferably stretched thereabout. A holding, stretching or tensioning arrangement for a printing machine cylinder cover is described in the referenced U.S. Pat. No. 2,209,127, the disclosure of which is hereby incorporated by reference. This reference teaches holding printing plates on a plate cylinder, using a tensioning and holding arrangement in which two ends of a substrate carrying the printing plate as such are introduced into recesses of a clamping strip. The recesses are located on circumferentially even levels. The tensioning strip is then tightened by screws extending therethrough and threaded in the bottom of the cylinder groove, to move the tensioning strip in the direction of the center of the cylinder.
It has been found that it is difficult to obtain uniform tensioning of the cover across the axial extent of the cylinder since a plurality of screws, distributed over the length of the cylinder must be tightened. Uniform tightening of the screws at the same time is necessary for uniform stretching of the cover. To uniformly tighten a plurality of screws requires either a substantial number of operators or machinists, with consequent high personnel cost, or an expensive and complex apparatus.